有氧运动与饮食干预对肥胖小鼠睾丸氧化应激的影响

Effects of aerobic exercise and dietary intervention on testicular oxidative stress in obese mice

目的:通过对肥胖小鼠施加有氧运动与饮食干预,探索运动与饮食干预对肥胖小鼠睾丸氧化应激和p38MAPK-NF-κB通路中的作用。方法:随机将17只C57BL/6J小鼠分为正常饮食组(ND),37只分为高脂饮食组(HFD),高脂饮食脂肪占比40%,喂养12周后,HFD组剔除3只肥胖抵抗小鼠,其余34只肥胖造模成功;随后将ND组分为正常饮食对照组(NC,n=8),正常饮食运动组(NE,n=9),肥胖高脂饮食对照组(OC,n=8),肥胖高脂饮食运动组(OE,n=9),肥胖正常饮食组(ONC,n=8),肥胖正常饮食运动组(ONE,n=9),各组继续饲养8周,其中NE、OE和ONE组以速度20 m/min,60 min/d,6 d/week,进行8周跑台运动,末次运动后36~40 h取血和睾丸组织,ELISA检测血清睾酮和睾丸氧化应激(MDA、T-SOD、T-AOC)水平,RT-PCR和Western blot检测睾丸p38MAPK-NF-κB水平。结果:与NC组比较,OC组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显升高(P<0.01),睾丸SOD、睾丸系数和血睾酮明显降低(P<0.01);NE组小鼠体脂参数明显降低(P<0.05),血清睾酮明显升高(P<0.01)。与OC组比较,OE组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显降低(P<0.05或0.01),睾丸SOD和血睾酮水平明显升高(P<0.01);ONC组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显降低(P<0.01),睾丸SOD水平和睾丸系数明显升高(P<0.05);ONE组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显降低(P<0.01),睾丸SOD、睾丸系数和血睾酮水平明显升高(P<0.01)。结论:肥胖引起小鼠睾丸发生氧化应激,上调睾丸p38MAPK-NF-κB水平,并降低血睾酮水平;运动、饮食和运动×饮食干预均能通过降低体脂,改善睾丸氧化应激,下调睾丸p38MAPK-NF-κB水平。

Objective:Through aerobic exercise and diet intervention on obese mice,the effects of exercise and diet intervention on testicular oxidative stress and p38MAPK-NF-κB pathway were investigated in obese mice.Methods:Seventeen C57BL/6J mice were randomly divided into a normal diet group(ND),and 37 mice were divided into a high-fat diet group(HFD),the high-fat diet accounted for 40%of fat.After 12 weeks of feeding,3 obesity-resistant mice were excluded from the HFD group,and the remaining 34 were successfully modeled.The mice in ND group were then divided into normal diet control group(NC,n=8)and normal diet and exercise group(NE,n=9).The mice in HFD group were divided into obese high-fat diet control group(OC,n=8),obese high-fat diet and exercise group(OE,n=9),obese normal diet group(ONC,n=8),and obese normal diet and exercise group(ONE,n=9).Each group continued to feed for 8 weeks,and the NE,OE and ONE groups performed treadmill exercise for 8 weeks at a speed of 20 m/min,60 min/d,6 d/week.Blood and testicular tissue samples were collected 36~40 h after the last exercise.Serum testosterone and testicular oxidative stress(MDA,T-SOD,T-AOC)levels were detected by ELISA,and testicular p38MAPK-NF-κB levels were detected by RT-PCR and Western blot.Results:Compared with the NC group,the body fat parameters,testicular MDA and testicular p38MAPK-NF-κB mRNA and protein levels in the OC group were increased significantly(P<0.01),while the levels of testicular SOD,testis coefficient and blood testosterone were decreased significantly(P<0.01);the body fat parameters of the mice in the NE group were decreased significantly(P<0.05),and the serum level of testosterone was increased significantly(P<0.01).Compared with the OC group,the body fat parameters,testicular MDA and testicular p38MAPK-NF-κB mRNA and protein levels were decreased significantly in the OE group(P<0.05 or 0.01),and the testicular SOD and blood testosterone levels were increased significantly(P<0.01);Body fat parameters,testicular MDA and testicular p38MAPK-NF-κB mRNA and protein levels were decreased significantly in ONC group(P<0.01),while testicular SOD level and testis coefficient were increased significantly(P<0.05);Body fat parameters,testicular MDA and testicular p38MAPK-NF-κB mRNA and protein levels of mice in ONE group were decreased significantly(P<0.01),while testicular SOD,testis coefficient and blood testosterone levels were increased significantly(P<0.01).Conclusion:Obesity induces oxidative stress in the testis of mice,up-regulates the level of p38MAPK-NF-κB,and reduces the level of blood testosterone;exercise,diet and exercise*diet interventions can reduce testicular oxidative stress and down-regulate testicular p38MAPK-NF-κB levels by reducing body fat.